1. Field of the Invention
The present invention relates to the chlorination of nitrophenols and, more especially, to the chlorination of nitrophenols using gaseous chlorine.
2. Description of the Prior Art
The chloronitrophenols are known compounds, and 2,6-dichloro-4-nitrophenol, for example, is a valuable chemical intermediate, useful in agrochemistry, after hydrogenation to 4-amino-2,6-dichlorophenol, or as a pharmaceutical intermediate after methylation of the phenol group.
2,4-Dichloro-6-nitrophenol can be used, in particular, as an enzyme inhibitor.
The monochloronitrophenols can be used as fungicides, or as intermediates for the preparation of other fungicides.
The chlorination of a nitrophenol is, however, difficult, since the presence of the NO.sub.2 group on the benzene ring strongly deactivates the molecule.